Thumb Pronation Angle in Thumb Opposition Evaluated by the Nail Tip Angle of Thumb-Ring Finger Opposition.

BACKGROUND: This study aimed to devise the method for the evaluation of the thumb pronation angle and calculate its reference value. METHODS: The study was conducted from October 2021 to March 2022, and 600 hands of 300 healthy volunteers were included in this study. The participants were divided into 6 age groups with 50 participants each. In study 1, 12 participants from group 1 were randomly selected, which included 6 male and 6 female participants. We measured the thumb pronation angle using FASTRAK system and the nail tip angle of thumb-ring finger opposition (T-R angle) and also evaluated the relation between them. In study 2, we measured the T-R angle of 600 hands of 300 healthy volunteers. The T-R angle mean (SD) and 95% confidence interval (CI) of each age group were calculated as reference values. RESULTS: The thumb pronation angle was correlated with the T-R angle. The T-R angle mean (SD) and 95% CI of the 6 groups were as follows: group 1, 142.5° (12.4) and 117.7 to 167.3; group 2, 139.9° (10.1) and 119.7 to 160.1; group 3, 142.3° (9.7) and 122.9 to 160.5; group 4, 140.2° (12.6) and 115.0 to 165.4; group 5, 138.3° (11.9) and 114.5 to 162.1; and group 6, 135.4° (13.0) and 109.4 to 161.4. The 95% CI tended to decrease with an increasing age. CONCLUSIONS: The T-R angle was a suitable evaluation method for the thumb pronation angle, and it should be evaluated by age groups.

The impact of postoperative inclination of the joint line on clinical outcomes in total knee arthroplasty using a prosthesis with anatomical geometry.

The goal of this study was to investigate the impact of postoperative inclination of the joint line on clinical results after total knee arthroplasty (TKA) using a prosthesis with anatomical geometry. This study included 145 primary cruciate-retaining type of knee prosthesis with anatomical geometry. Three years postoperatively, clinical outcomes including the patient-reported outcomes (PROs) were recorded. Limb alignment was evaluated by the hip-knee-ankle (HKA) axis and inclination of the joint line was assessed by the joint line orientation angle (JLOA). Knees were divided into two groups according to the HKA: in-range (- 3 to 3°) and outlier group (< - 3° or > 3°) or the JLOA: in-range (2-4°) and outlier group (< 2° or > 4°), and clinical outcomes were compared between the groups. Postoperative Knee Society Function Score (KS-FS) was significantly higher in the HKA in-range group than the outlier group (p = 0.01). The Knee Society Knee Score and all subscales of the Knee injury Osteoarthritis Outcome Score were comparable between the groups. A multivariate analysis revealed a significant association between age at operation and postoperative KS-FS > of 80 points. Neither HKA in-range nor JLOA in-range were associated with the higher knee function. In conclusion, TKA-postoperative inclination of the joint line was not relevant to the short-term PROs. Treatment strategies that attempt to make joint line inclination in order to improve postoperative PROs should be avoided, and alignment goals such as kinematic alignment should be considered carefully.

Lateral shift of the femoral condyle after total knee arthroplasty: simulation using 2D-templates of the medial pivot design on knee radiographs of young Japanese patients.

BACKGROUND: Total knee arthroplasty (TKA) is an established surgical treatment for advanced knee osteoarthritis by which patients can expect improvement of knee pain and function. Although many surgeons have investigated limb alignment after TKA, changes in coronal positional relation between the femur and tibia are not known well. METHODS: Radiographs of 105 knees of young Japanese patients between 20 and 49 years-old (60 men and 45 women) without osteoarthritic changes who received arthroscopic surgeries at our hospital were used in this study. Using 2D-templates of the medial pivot design (the FINE total knee), we simulated TKA on a SYNAPSE-PACS software. First, the femoral component was placed in normal knee alignment and then was merged to the medial concave of the insert where the tibial component was placed in neutral alignment. The length of the mediolateral shift of the femoral component was measured as an estimate of lateral shift of the femoral condyle, of which association with radiographic parameters including the femorotibial angle (FTA), lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA) was analyzed. Subjects were classified into three groups according to the femoral component size that was chosen in simulation of TKA, and the lateral shift of the femoral condyle was compared between groups. RESULTS: The estimated mean lateral shift of the femoral condyle was 5.99 ± 1.98 mm and was greater in males than females (p < 0.05). Also, it was most highly correlated with the medial proximal tibial angle (MPTA) (r = - 0.553, p < 0.01). A group receiving larger component sizes significantly shifted more laterally compared with a group receiving smaller component sizes (p < 0.01). CONCLUSIONS: These results suggest that the coronal positional relation between the femur and tibia is altered and subsequent ligament imbalance may occur after mechanically aligned TKA using the medial pivot design.

Serum Reactive Oxygen Metabolites as a Predictor of Clinical Disease Activity Index, Simplified Disease Activity Index, and Boolean Remissions in Rheumatoid Arthritis Patients Treated With Biologic Agents.

Introduction Reactive oxygen metabolites (ROMs) are metabolite hydroperoxides in the blood, and their serum levels were associated with the disease activity score 28 (DAS28) in patients with rheumatoid arthritis (RA). In this study, we aimed to investigate whether ROMs would be predictive of the clinical disease activity index (CDAI) remission, simplified disease activity index (SDAI) remission, or Boolean remission. Materials and methods Fifty-one biologic agents (BA)-naïve RA patients were included in this observational study. Associations between ROMs, C-reactive protein, matrix metalloproteinase-3, DAS28-erythrocyte sedimentation rate (ESR), CDAI, SDAI, and health assessment questionnaire (HAQ) at 12 weeks and the DAS28, CDAI, SDAI, and Boolean remission rates at 52 weeks were investigated. Results The DAS28, CDAI, SDAI, and Boolean remission rates at 52 weeks were 66.7, 52.9, 54.9, and 54.9%, respectively. A multivariate logistic regression analysis revealed that ROMs and HAQ at 12 weeks were associated with the CDAI, SDAI, and Boolean remission at 52 weeks. Receiver operating characteristic analyses demonstrated that the cut-off value for CDAI, SDAI, and Boolean remission was 389.5 U.Carr. Conclusion Reactive oxygen metabolites at 12 weeks of initial treatment with BAs was a predictor for CDAI, SDAI, and Boolean remission at 52 weeks. Serum levels of ROMs may be a useful biomarker in the current treatment strategy aiming at early remission of RA.

Delayed surgical site infection after posterior cervical instrumented surgery in a patient with atopic dermatitis: a case report.

Objective: Atopic dermatitis (AD) is one of the known risk factors for Staphylococcus aureus infection. The authors report the case of a patient with cervical spondylosis and AD who developed delayed surgical site infection after posterior cervical instrumented surgery. Patient: A 39-year-old male presented to our hospital with paralysis of the left upper extremity without any cause or prior injury. He had a history of severe AD. We performed C3-C7 posterior decompression and instrumented fusion based on the diagnosis of cervical spondylotic amyotrophy. One year after surgery, his deltoid and bicep muscle strength were fully recovered. Nevertheless, his neck pain worsened 2 years after surgery following worsening of AD. One month after that, he developed severe myelopathy and was admitted to our hospital. Radiographic findings showed that all the screws had loosened and the retropharyngeal space had expanded. Magnetic resonance imaging and computed tomography showed severe abscess formation and destruction of the C7/T1 vertebrae. Result: We diagnosed him with delayed surgical site infection. Methicillin-resistant Staphylococcus aureus was identified on abscess culture. The patient responded adequately to treatment with antibiotic therapy and two debridements and the infection subsided. Conclusion: We should consider the possibility of delayed surgical site infection when conducting instrumented spinal surgery in patients with severe AD.

Biomechanics of callus in the bone healing process, determined by specimen-specific finite element analysis.

As fractures heal, immature callus formed in the hematoma is calcified by osteoblasts and altered to mature bone. Although the bone strength in the fracture-healing process cannot be objectively measured in clinical settings, bone strength can be predicted by specimen-specific finite element modeling (FEM) of quantitative computed tomography (qCT) scans. FEM predictions of callus strength would enable an objective treatment plan. The present study establishes an equation that converts material properties to bone density and proposes a specimen-specific FEM. In 10 male New Zealand white rabbits, a 10-mm long bone defect was created in the center of the femur and fixed by an external fixator. The callus formed in the defect was extracted after 3-6 weeks, and formed into a (5 × 5 × 5 mm3) cube. The bone density measured by qCT was related to the Young's modulus and the yield stress measured with a mechanical tester. For validation, a 10-mm long bone defect was created in the central femurs of another six New Zealand white rabbits, and fixed by an external fixator. At 3, 4, and 5 weeks, the femur was removed and subjected to Computed tomography (CT) scanning and mechanical testing. A specimen-specific finite element model was created from the CT data. Finally, the bone strength was measured and compared with the experimental value. The bone mineral density σ was significantly and nonlinearly correlated with both the Young's modulus E and the yield stress σ. The material-property conversion equations were E = 0.2391e8.00ρ and ρ = 30.49σ2.41. Moreover, the experimental bone strength was significantly linearly correlated with the prospective FEM. We demonstrated the Young's moduli and yield stresses for different bone densities, enabling a FEM of the bone-healing process. An FEM based on these material properties is expected to yield objective clinical judgment criteria.

Time Course of Changes in Serum Oxidative Stress Markers to Predict Outcomes for Surgical Treatment of Lumbar Degenerative Disorders.

Recent reports indicate that oxidative stress is involved in the pathobiology of acute spinal cord injury or compression myelopathy. We conducted an observational study to determine levels of oxidative stress markers in serum from 80 patients who underwent spinal surgery to treat neurological symptoms related to lumbar degenerative disorders. Serum samples were collected before surgery and at 3 months, 6 months, and 1 year after surgery. Derivatives of reactive oxygen metabolites (ROM) in the serum samples were measured to gauge the level of oxidative stress. For preoperative neurological evaluation, patients were assessed for motor weakness in the lower extremities. We divided the patient samples into two groups: ROM decreasing at 1 year after surgery (G group) and ROM increasing at 1 year after surgery (W group). Then, we evaluated clinical outcomes using the visual analog scale and Oswestry disability index (ODI). Among the samples from the 80 enrolled patients, mean ROM levels before surgery increased to 388.5 ± 92.0, indicating the presence of moderate oxidative stress. The level of ROM gradually decreased after surgery and 1 year after surgery: the levels had significantly decreased to 367.6 ± 83.3 (p < 0.05). In patients who exhibited motor weakness, ROM values were significantly increased compared to those patients who had no motor weakness (p < 0.05). In analyses of clinical outcomes, ODI values for the W group 1 year after surgery were significantly higher than those for the G group (p < 0.05). Moderate oxidative stress was present in patients who had lumbar degenerative disorders and the degree of oxidative stress gradually improved within 1 year after surgery. The clinical results suggest that neurogenic oxidative stress can be mitigated by surgery for patients with lumbar degenerative disorders, and residual oxidative stress reflects poor surgical outcomes.

Nutritional status as the risk factor of serious infection in patients with rheumatoid arthritis.

Objectives: The aim of this study was to identify the risk factors associated with severe infection in RA patients, with a particular focus on the association of the nutritional status.Methods: We retrospectively analyzed data from 74 patients with RA (male, n = 21; female, n = 53; age 74.2 ± 12.4) admitted to our hospital between 2016 and 2017 for infection (infection group). We also recruited control RA patients (n = 222) who were matched for age, gender and disease duration, with a match ratio of 1:3 (non-infection group). The nutritional condition was assessed based on controlling nutrition status (CONUT) score, and prognostic nutritional index (PNI). The data of the infection group were obtained from the most recent visit prior to the present admission, and non-infection group from the last regular visit in 2017.Results: The respiratory tract was the most frequent site of infection. The BMI and PNI were significantly lower and the CONUT score significantly higher in the infection group than in the non-infection group. A logistic regression analysis revealed that the CONUT score, underlying lung disease and use of prednisolone and biological disease-modifying anti-rheumatic drugs were independent and significant risk factors for serious infection.Conclusion: Poor nutritional status increases the risk of serious infection.

Serum oxidative stress influences neurological recovery after surgery to treat acutely worsening symptoms of compression myelopathy: a cross-sectional human study.

BACKGROUND: Recent reports indicate that oxidative stress induced by reactive oxygen species is associated with the pathobiology of neurodegenerative disorders that involve neuronal cell apoptosis. Here we conducted a cross-sectional study to evaluate serum levels of oxidative stress in cervical compression myelopathy. METHODS: Thirty-six serum samples were collected preoperatively from patients treated for acutely worsening compression myelopathy (AM) and chronic compression myelopathy (CM). Serum levels of oxidative stress markers were evaluated by measuring derivatives of reactive oxygen metabolites (ROM), which reflect concentrations of hydroperoxides. ROM in healthy individuals range from 250 to 300 (U. CARR), whereas ROM >340-400 and > 400 define moderate and severe levels of oxidative stress, respectively. Difference of ROM by the cause of disorders whether cervical spondylotic myelopathy (CSM) or cervical ossification of longitudinal ligament (OPLL), correlations between ROM and patient age, body mass index (BMI), history of smoking, existence of diabetes were examined. Neurological evaluations according to Japanese Orthopaedic Association (JOA) scores were performed and correlated with ROM. RESULTS: ROM increased to 349.5 ± 54.8, representing a moderate oxidative stress, in CM samples. ROM increased to 409.2 ± 77.9 in AM samples, reflecting severe oxidative stress which were significantly higher than for CM samples (p < 0.05). There was no significant difference by the cause of disorders (CSM or OPLL). ROM were significantly increased in AM serum samples from female patients versus AM male and CM patients (p < 0.05). There were no correlations between ROM and age, BMI, history of smoking, and existence of diabetes. A negative correlation between ROM and recovery rate of JOA score (R2 = 0.454, p = 0.047) was observed in the AM group. CONCLUSIONS: Although moderate oxidative stress was present in patients with CM, levels of oxidative stress increased in severity in patients with AM. These results suggest that postsurgical neurological recovery is influenced by severe oxidative stress in AM.

Intradural metastasis to the cauda equina found as the initial presentation of breast cancer: a case report.

BACKGROUND: Intradural extramedullary spinal metastasis is a relatively rare condition. Furthermore, there are few reports with the initial presentation being a neurological symptom from an intradural metastasis. We report a case of a patient with metastasis to the cauda equina from breast cancer found due to neurological symptoms as the initial presentation. CASE PRESENTATION: A 76-year-old Japanese woman who was previously healthy presented to our hospital with bilateral severe buttock and lower extremity pain without any history of injury. A solitary intradural cauda equina mass was found by magnetic resonance imaging at the L2/3 level, and we suspected a schwannoma initially. The patient hoped to undergo surgery due to the severe pain. However, the chest computed tomographic scan obtained to assess the patient's general status showed the suspected breast cancer of the left side and a lung metastasis. Hence, we considered the possibility of cauda equina tumor metastatic from the breast cancer. We performed an L1-3 laminectomy and tumor extirpation. The pathology revealed adenocarcinoma. After surgery, she had relief from pain, and her status remained satisfactory until she died 9 months after surgery. CONCLUSIONS: It is difficult to clarify whether the cauda equina tumor is benign or malignant based only on Magnetic resonance imaging findings. Clinicians should consider the possibility of metastasis when planning the surgery for intradural cauda equina tumor extirpation.

Unilateral laminectomy for bilateral decompression improves low back pain while standing equally on both sides in patients with lumbar canal stenosis: analysis using a detailed visual analogue scale.

BACKGROUND: Unilateral laminectomy for bilateral decompression (ULBD) for lumbar spinal stenosis (LSS) is a less invasive technique compared to conventional laminectomy. Recently, several authors have reported favorable results of low back pain (LBP) in patients of LSS treated with ULBD. However, the detailed changes and localization of LBP before and after ULBD for LSS remain unclear. Furthermore, unsymmetrical invasion to para-spinal muscle and facet joint may result in the residual unsymmetrical symptoms. To clarify these points, we conducted an observational study and used detailed visual analog scale (VAS) scores to evaluate the characteristics and bilateral changes of LBP and lower extremity symptoms. METHODS: We included 50 patients with LSS treated with ULBD. A detailed visual analogue scale (VAS; 100 mm) score of LBP in three different postural positions: motion, standing, and sitting, and bilateral VAS score (approached side versus opposite side) of LBP, lower extremity pain (LEP), and lower extremity numbness (LEN) were measured. Oswestry Disability Index (ODI) was used to quantify the clinical improvement. RESULTS: Detailed LBP VAS score before surgery was 51.5 ± 32.5 in motion, 63.0 ± 30.1 while standing, and 37.8 ± 31.8 while sitting; and showed LBP while standing was significantly greater than LBP while sitting (p < 0.01). After surgery, LBP while standing was significantly improved relative to that while sitting (p < 0.05), and levels of LBP in the three postures became almost the same with ODI improvement. Bilateral VAS scores showed significant improvement equally on both sides (p < 0.01). CONCLUSIONS: ULBD improves LBP while standing equally on both sides in patients with LCS. The improvement of LBP by the ULBD surgery suggests radicular LBP improved because of decompression surgery. Furthermore, the symmetric improvement of LBP by the ULBD surgery suggests unsymmetrical invasion of the paraspinal muscles and facet joints is unrelated to residual LBP.

Predictive factors for radiographic progression of large joint damage in patients with rheumatoid arthritis treated with biological disease-modifying antirheumatic drugs (bDMARDs): Results of 3 to 4 years of follow-up.

Objectives: Little information is available regarding long-term follow-up of radiographic progression of damage (RPD) to large joints during treatment of rheumatoid arthritis (RA) with biological disease-modifying antirheumatic drugs (bDMARDs). We evaluated 3- to 4-year follow-up results and the associations between RPD and patient background and Larsen grade (LG) of joints.Methods: Seventy-one RA patients receiving bDMARDs for 3 to 4 years or who achieved bDMARD-free status were included. The mean age and disease duration at the start of bDMARDs were 62.4 years and 10.8 years, respectively. A total of 314 joints, including shoulders, elbows, hips, knees, and ankles, were evaluated to determine whether RPD was present by comparing radiographs before and after treatment.Results: RPD was observed in 24 patients (33.8%) and 34 joints (10.8%). Joints with an LG of III or higher had significantly higher rates of RPD than those with LGs I and II. Multivariate logistic regression analysis revealed that stage and health assessment questionnaire (HAQ) score at 18-months were independent risk factors for RPD (cut-off value: 2.5, odds ratio: 7.222 for stage; cut-off value: 0.9375, odds ratio: 6.278 for HAQ at 18-months).Conclusion: Stage, HAQ at 18-months, and LG at the start of bDMARDs were predictive of RPD after 3 to 4 years. bDMARDs should be started before both stage and LG exceed III and the therapeutic strategy should be determined so that HAQ does not exceed 1.0 during treatment.

Serum levels of reactive oxygen metabolites at 12 weeks during tocilizumab therapy are predictive of 52 weeks-disease activity score-remission in patients with rheumatoid arthritis.

BACKGROUND: To verify whether serum levels of reactive oxygen metabolites (ROM) are predictive of future clinical remission in patients with rheumatoid arthritis (RA) receiving tocilizumab (TCZ) therapy. METHODS: A total of 46 patients with RA receiving TCZ therapy were enrolled in this study. Patients were divided into remission and non-remission groups based on disease activity score 28 (DAS28)-erythrocyte sedimentation rate (ESR) or clinical disease activity index (CDAI) at 52 weeks. Associations between serum levels of ROM, C-reactive protein (CRP), and matrix metalloproteinase-3 (MMP-3) at 4 and 12 weeks and the remission by DAS28-ESR and CDAI at 52 weeks were investigated. RESULTS: There were no significant differences in CRP and MMP-3 between DAS- or CDAI-remission and non-remission groups at 12 weeks. However, ROM in DAS-remission group were significantly lower than those in the non-remission group. For ROM, the area under the curve of the receiver operating characteristic curve was 0.735 and the cut-off value that distinguished DAS-remission group from non-remission group was 305.5 U. Carr (sensitivity: 70.0%, specificity: 72.2%). A multivariate logistic regression analysis revealed that ROM at 12 weeks was associated with DAS-remission at 52 weeks (odds ratio: 6.067, 95% confidence interval: 1.305-28.203). CONCLUSION: Serum levels of ROM at 12 weeks during TCZ therapy may be predictive of DAS-remission at 52 weeks in patients with RA.

Surgical treatment for dropped head syndrome with cervical spondylotic amyotrophy: a case report.

BACKGROUND: Dropped head syndrome (DHS) is a flexion deformity of the neck that is caused by severe weakness of the neck extensor muscles. DHS occurs in combination with not only neuromuscular disorders, but also cervical spondylosis. However, there are few reports of DHS complicated by cervical spondylotic amyotrophy (CSA). Here we report a case of DHS with CSA in a patient who underwent surgical treatment. CASE PRESENTATION: A 79-year-old man became aware of dropped head and gait disturbance in addition to the paralysis of his right upper extremity. At his initial visit, he had a severe chin-on-chest posture. Neurological examination revealed severe paralysis of deltoid, biceps, wrist extensor, finger flexor, extensor, and abductors, in addition to lower extremity spasticity. Nevertheless, sensory dysfunction was not observed. X-ray images showed severe kyphosis at the upper thoracic level. MRI and CT myelography findings revealed spinal canal stenosis at the level of C5-6 and C6 root compression of the right side. Motor neuron disease was excluded because of findings from electromyography. Therefore, we diagnosed this patient as having DHS with cervical spondylotic amyotrophy. A C2-Th5 posterior fusion with C3-C6 laminoplasty and C5-6 foraminotomy on the right side were performed. After surgery, the complaint of dropped head was improved significantly and bilaterally finger motion was improved slightly. His neck position was maintained at the final follow-up at about 1 year after surgery. CONCLUSIONS: Despite the limitation of short-term follow-up, favorable results for the DHS were maintained in the present case. Surgical treatment for similar cases may be a feasible option, but surgery does have some complications.

Lower early postnatal oxygen saturation target and risk of ductus arteriosus closure failure.

BACKGROUND: Early postnatal hyperoxia is a major risk factor for retinopathy of prematurity (ROP) in extremely premature infants. To reduce the occurrence of ROP, we adopted a lower early postnatal oxygen saturation (SpO2 ) target range (85-92%) from April 2011. Lower SpO2 target range, however, may lead to hypoxemia and an increase in the risk of ductus arteriosus (DA) closure failure. The aim of this study was therefore to determine whether a lower SpO2 target range, during the early postnatal stage, increases the risk of DA closure failure. METHODS: Infants born at <28 weeks' gestation were enrolled in this study. Oxygen saturation target range during the first postnatal 72 h was 84-100% in study period 1 and 85-92% in period 2. RESULTS: Eighty-two infants were included in period 1, and 61 were included in period 2. The lower oxygen saturation target range increased the occurrence of hypoxemia during the first postnatal 72 h. Prevalence of DA closure failure in period 2 (21%) was significantly higher than that in period 1 (1%). On multivariate logistic regression analysis, the lower oxygen saturation target range was an independent risk factor for DA closure failure. CONCLUSION: Lower early postnatal oxygen saturation target range increases the risk of DA closure failure.

Phosphorylated neurofilament subunit NF-H becomes elevated in the cerebrospinal fluid of patients with acutely worsening symptoms of compression myelopathy.

It is known that the severity of compression myelopathy sometimes worsens rapidly and results in poor functional recovery because of limited axonal regeneration. Levels of phosphorylated neurofilament subunit NF-H (pNF-H), which indicate axonal degeneration, are elevated in other neurological disorders. To our knowledge, there has been no examination of pNF-H levels in compression myelopathy. Therefore, we conducted a pilot cross-sectional study to evaluate pNF-H levels in the cerebrospinal fluid (CSF) of patients with worsening symptoms of cervical compression myelopathy. From January 2011 to March 2013, 51 samples of CSF were collected from patients at the time of myelography before spinal surgery. The indications for surgery were acutely worsening compression myelopathy (AM) in eight, chronic compression myelopathy (CM) in six, and lumbar canal stenosis (LCS) in 37 patients. The pNF-H levels were measured using a standard enzyme-linked immunosorbent assay. The mean ± standard deviation pNF-H value was 2127.1 ± 556.8 pg/ml in AM patients, 175.8 ± 67.38 pg/ml in CM patients and 518.7 ± 665.7 pg/ml in LCS patients. A significant increase in pNF-H levels was detected in the CSF of patients with AM compared with those with either CM or LCS. The clinical outcome of surgical treatment for patients with cervical myelopathy was satisfactory in both AM and CM patients. Despite the limitations of small sample size and lack of healthy CSF control data due to ethical considerations, our results suggest that pNF-H in CSF can act as a biomarker that reflects the severity of AM.

Identification of clinical parameters associated with serum oxidative stress in patients with rheumatoid arthritis.

OBJECTIVES: Reactive oxygen species (ROS) are considered to be involved in the pathobiology of rheumatoid arthritis (RA); however, their association with disease activity has not been elucidated. In this study, we measured reactive oxygen metabolites (ROM) in patients with RA using a new Free Radical Analytical System and determined clinical parameters associated with ROM. METHODS: One hundred and fifty-two patients with RA and 80 patients with diabetes mellitus (DM) were included in this observational study. To measure ROM, the d-ROM test was performed on blood samples drawn from all subjects. The correlation between ROM and biomarkers, disease activity, doses of methotrexate (MTX), and prednisolone (PSL) were investigated. RESULTS: There were significant, positive correlations between ROM and CRP, matrix metalloproteinase 3 (MMP3), Disease Activity Score 28-erythrocyte sedimentation rate (DAS28-ESR), Clinical Disease Activity Index (CDAI), and the Simplified Disease Activity Index (SDAI). Multiple regression analysis revealed that CRP and DAS28-ESR were correlated with ROM. CONCLUSIONS: The serum level of ROM was associated with CRP and DAS28-ESR, suggesting that ROM, in conjunction with CRP and MMP3, may be able to be used as a new biological disease marker to evaluate the disease activity of RA.